Kastin A J, Akerstrom V
Veterans Affairs Medical Center, Tulane University School of Medicine, New Orleans, Louisiana 70112-1262, USA.
Am J Physiol. 1999 Nov;277(5):E901-4. doi: 10.1152/ajpendo.1999.277.5.E901.
Cocaine- and amphetamine-regulated transcript (CART) is a new anorectic peptide found in the brain and periphery. It is closely associated with leptin, an anorectic agent saturably transported across the blood-brain barrier (BBB). Using multiple time-regression analysis, we found that CART has a rapid rate of entry into brain from blood. However, there was no self-inhibition with CART, even when perfused in blood-free buffer or in fasted mice, showing a lack of saturation. HPLC showed that at least 58% of the injected CART reached brain tissue in intact form, and capillary depletion with and without washout showed that the CART was not bound to endothelial cells or adherent to vascular components. There was no evidence for an efflux system out of the brain for CART. Thus CART can cross the BBB from blood to brain, but its rapid rate of entry is not inhibited by excess CART or leptin.
可卡因和苯丙胺调节转录物（CART）是一种在大脑和外周发现的新型厌食肽。它与瘦素密切相关，瘦素是一种通过血脑屏障（BBB）进行饱和转运的厌食剂。通过多次时间回归分析，我们发现CART从血液进入大脑的速度很快。然而，即使在无血缓冲液中灌注或在禁食小鼠中，CART也没有自我抑制作用，表明缺乏饱和现象。高效液相色谱法显示，至少58%注入的CART以完整形式到达脑组织，有冲洗和无冲洗的毛细血管耗竭表明CART不与内皮细胞结合或附着于血管成分。没有证据表明存在CART从大脑流出的外排系统。因此，CART可以从血液穿过血脑屏障进入大脑，但其快速进入速度不受过量CART或瘦素的抑制。
